Hindsight bias: after the match, he always knew

The match is over. India has lost in the last over, and in your PG room in Pune your friend Rohan puts down his plate and says, "I knew it. I knew we would lose." At the toss, three hours earlier, he said nothing. He was busy arguing about who ordered the extra biryani.

Rohan is not lying. He really does feel that he knew. That feeling has a name.

What the model is

Hindsight bias is what happens to your memory once you know how something ended. The result walks backwards and tidies up the past. What was uncertain before starts to look obvious, and you remember yourself as more sure than you were. The idea comes from the research of the psychologist Baruch Fischhoff, who compared what people predicted before an event with what they later remembered predicting.

The match, played again

Go back to the toss. The captain wins it and chooses to bowl first. At that moment, here is what anyone in the room has: the pitch looks dry, there may be dew later, the other side chases well. Nobody has the score. If you had asked Rohan then, he might have said, "Could go either way."

Then the result arrives, and three things happen quickly.

First, the loss feels as if it was always coming. The dropped catch in the twelfth over stops being bad luck and becomes a sign.

Second, Rohan's memory of the toss changes. "Could go either way" quietly becomes "I had a bad feeling."

Third, the decision gets its marks from the result. Bowling first is now "a stupid call", only because the match was lost. If the same call had ended in a win, the same Rohan would call it brave.

That third step is the unfair one. A decision is made with what you know at the time. The result also carries luck: a catch, a no-ball, the dew that did not come. A good decision can end badly, and a careless one can end well. Judging the decision by the result alone mixes the two.

It does not stay in cricket. It is the relative who says "I told you that marriage wouldn't work", though at the wedding he took two helpings and said nothing. It is you, after the market falls, telling yourself you saw it coming.

The trap

Hindsight bias does not mean every bad result was bad luck. Sometimes the call really was careless, and "nobody could have known" becomes a comfortable excuse. The fair question is not "how did it end?" It is "what did I know then, and was the choice reasonable with that?" Without a record you cannot answer it, because your memory has already been edited.

One thing to try today

Start a decision journal, and keep it small. Before tonight, pick one thing whose result you do not know yet: tomorrow's match, a job application, a plan for the weekend. In your phone's notes, write three lines with today's date: what you expect, how sure you are out of ten, and the one reason behind it. Do not edit it later. When the result comes, read the note before you say what you knew. The first few times it feels slow and a bit silly.

This is a way to think, not financial, medical or legal advice.

Each Sunday: one mental model and one real decision to try it on, from the model library.